Premiering in the first Street Fighter, Ryu appears as the lead character from the game along with his best friend Ken participating in the Street Fighter tournament. Further games from the series show Ryu to be highly focused on his training, aiming to become the strongest he can. However, his powers also attract several criminals who want to use him for their plans.

Ryu has been the lead character of the Street Fighter series since the first game and has appeared in crossovers involving the franchise. He is also featured in manga from the series, anime adaptations and the 1994 live-action film. According to most fighting game fans, Ryu is arguably the most recognizable and influential fighting game character.

In the first Street Fighter game, Ryu has red hair and wears a tattered white karate gi with a white hachimaki (headband), red gloves and red shoes. Also, a constant trait in his design is the kanji motif (meaning Wind, Forest, Fire, Mountain), battle standard of the historical Japanese military leader Takeda Shingen, embroidered into his obi, simulating Karate Dan degrees. In Street Fighter II Ryu is shown to be older, with brown hair and a red hachimaki. He also fights barefooted this time. The Alpha series features a Ryu much like the one depicted in the original Street Fighter, with light red hair and a white hachimaki. In the Street Fighter III games, Ryu has black hair and facial stubble to show his growth in age. Street Fighter IV is chronologically set between II and III and so Ryu has a more mature look than he does in Street Fighter II but still not as aged looking as in Street Fighter III.